Lubricator with secondary air circuit



Aug. 14, 1951 c. A. NORGREN 2,564,309

LUBRICATOR WITH SECONDARY AIR CIRCUIT Ffiled Oct. 12, 1949 INVENTOR.Carl A. Norgren ATTORNEY Patented Aug. 14, 1951 LUBRICATOR WITHSECONDARY AIR" v GIRCUIT Qarl A, Norgren, lDenver, Coltig'assig nor toC. A.

Norgren Denver, 0010., a corporation of Colorado Application bathe,- 12,1949-, Serial 1%.126353 My invention refers to air line lubricators,particularly of the type adapted to deliver a very small quantity of oilto air flowing under pressure through the lubricator.

Several air line lubricators are currently available for deliveringquantities of oil, such as several drops of oil per minute, to a streamof air flowing through the lubricator to a tool or other compressed airmachine requiring lubrication. The rate of oil delivery from theselubricators is usually controlled by a needle valve or similarmechanism, which is reasonably satisfactory in instances where oil flowson the order of several drops per minute are required, since under suchconditions; the orifice opening in the valve is fairly large. If,however, oil flowsv on the order of one or two drops per minute, or evenone drop in two or more minutes are required, these lubricators becomeunsatisfactory since it is neces-v sary, under such circumstances, topractically close the needle valve, leaving only a very small orificethrough which the oil must pass. The oil usually contains minor amountsof small solid particles and in addition usually tends to oxidize orform a gum which, in a relatively short time, wholly or partially blocksthe small orifice, thus reducing or completely stopping the flow of.oil. Regulation of the oil flow under these circumstances is, therefore,not only difficult but is usually impossible to maintain over anextended period of time without continuous attention.

One of the primary objects of my invention is to overcome the above andother defects in known air line lubricators by providing an air linelubricator which will consistently deliver to a stream of air passingthrough my lubricator a small predetermined quantity of oil at arelatively constant rate over an extended period of time.

Other important objects of my invention include the provision of alubricator of the'type described which incorporates means for regulatingthe flow of oil and which, when regulated to discharge only a very smallquantity of oil per minute, does not restrict the oil passage to adegree which renders probable the complete or partialblocking of theregulating orifice.

Other objects of my invention reside in various novel components andcombinations thereof which are fully disclosed, together with theseveral advantages of my invention, in the following detaileddescription and in the appended drawing in which:

The figure of the drawing is a partial vertical cross section through mylubricator.

As illustrated, my lubrlcator includes a body- 6 Claims. (order-55) 45portion E3 of the conduit H.

' In in which is formed an air conduit, generally designated ll, throughwhich air under pressure passes from an inlet portion l2,'through acenter portion l3, and an outlet portion l4 to a tool or other mechanismrequiring lubrication. The cross sectional area of the center portion I3is less than the cross sectional area of either the inlet portion |2 orthe outlet portion l4, thus requiring air passing through the conduit Hto travel at a greater velocity through the center 0 section l3 andthereby create a zone of reduced pressure. A bowl I6, adapted to containlubricant such as oil, is sealed to the lower face of the body II] incontact with a gasket l1 and is held in position by a peripheral ring l8encompassing the bowl [6 and engaging lips l9 formed thereon.

Bolts 2| extend through the ring I 8 into engagement with the body l0.

A cylindrical metal gauge guard 22, having a plurality of openingsformed in its wall, is sealed to the upper face of the body Inimmediately above the center portion 13. A hollow cylindricaltransparent gauge glass 23, defining a chamber 38, is mounted within theguard 22 and rests upon a gasket 24. A gasket 26 extends around theupper edge of the gauge glass '23 and contacts a needle valve body 21,which extends downwardly a short distance into the gauge glass 23. A cap28 is threaded to the guard 22 and holds the valve body 21 in firmengagement with the gasket 26.

The valve body 21 is provided with an axial bore restricted at its lowerend to form a discharge orifice 29. A regulating screw 3| is threaded inthe bore and includes a conical point, the position of which controlsthe effective opening of the orifice 29. The valve body 21 also includesa small laterally extending passageway 32 which communicates with a bore33 formed in the gauge glass 23. A passage 34 formed in the body It!connects the passage 33 with a pendant tube 36,

the latter extending downwardly towards the lower portion of the bowlIS.

A passage. 31 extends through the body l0 interconnecting the lowerportion of the chamber 33, defined by the gauge glass 23 with the centerAnother passage 39, preferably in the form of a tube, interconnects theinlet portion I2 of the conduit II with the interior of the bowl l6,thus permitting the introduction of air at inlet pressure into the bowl.

Apassage 4|, preferably in the form of a tube,

extends from the inlet portion l2 into the chamber 38, preferablyterminating in the lower pork tion of said chamber. A baffle 42 may besecured to the tube 4! or otherwise and extends across the discharge endoi the tube 4|.

In operation by lubricator is inserted in an air line through which airis conveyed to atool or other mechanism :requiring lubrication. The bowl[6 is filled with oil and the rate of oil delivery adjusted by movementof the regulating screw 3|. When the air in the conduit I I is not inmotion, the pressures in the bowl is, and in the chamber 38 are equalwith a result that no oil is delivered. However, as the air flowsthrough the center portion l3, it creates a zone of reduced pressurewhich is, in turn, communicated to the chamber 38 through the passage31. The pressure in the bowl it is maintained at inlet pressure by thetube 39, thus creating a pressure differential which draws oilfrom thebowl it through the tube 36, passage 34, passage 33, passage 32 andorifice 29 into the chamber 32}. The oil falls from the orifice 29 inthe form of drops which eventually pass through the passage 37 into theconduit ll forming a fog which is carried bytheair stream to the tool-l;;,The ,maximum possible pressure differential is, not established in mylubricator, however, because of the tube ir'which is controlled as tolength. and bore to deliver to the chamber 35 a volume of ,air somewhatless than thatcapable of discharge through the passage 3?. The baifiedihhcing disposed over the discharge end of the tube 6!, prevents theturbulence of the'air enteringthroug-htube 41 from disturbing the form-wtion of anoildroplet at the orifice 2s. The air entering-from tube H isdrawn outwardly, together with the 'oil, through the passage 31 into theconduit H. I havefound that the oil falling in droplet form fromthe'orifice 29 is at least partially atomized before passing through theopening 31, the atomization being completed. upon discharge of the oilahd'air mixture from thep'assage Shinto the center portion l3.

since the effect or" the tube li is to reduce the pressurediiferehtaleffective for drawing oil into the stream of air passing through theconduit H, it will be found that the regulating sc rew 3i may be openeda "considerable distance even when flows on the order of a dropin two ormore minutes are desired, with the result that there is'very littletendency for the opening in the valve to clo'g either by the formationof gum around or near the orific" 29, or by the lodgernento f soil-iparticles in ,the valve. Furthermor'e, it is be--' lievedthat theatomization of the oil is considerably improved since a mixture of oiland air rather than oil alone passes through the passage 37. W t

It maybe seen thatth-e bore and len'gth the tube ti controls, by itsrelationship with the bore and length of passage 3?, the degree to whichthe-reflective pressure difierentialis reduced and this reduction may,therefore, be easily regulated in. the process of fabrication. It willalso be understood that the pressure of the air in the inlet portion I2is only slightlygreat'erth'an the pressure of the air in the outletportion Hi, both of these being greater than the pressure in the centerportion !3. The tube 4i may therefore interconnect the chamber 38 withthe outlet portion M if desired, although I do not consider such astructure as satisfactory as that illustrated in the figure.

The foregoing detailed description has been made in compliance with R.S. 4888 and constitutes a preferred embodiment of my invention. However,since various modifications in the cletails of construction will beobvious to those skilled in the art, I do not bind myself to. the

4 precise construction disclosed except insofar as defined in theappended claims.

I claim:

1. An air line lubricator comprising a body having an air conduit formedtherein including a zone of reduced cross sectional area, a bowl sealedto the lower surface of the body, a gauge glass sealed to the uppersurface of the body defining a chamber, said body having a first passagefor conveying air at inlet pressure into the bowl, 9. second passage forconveying oil from the bowl to the upper portion of the chamber, and athird passage interconnecting the lower portion of the chamber with thezone of reduced cross secti'onal area in the air conduit, a valve insaid second passage, and conduit means in the body for admitting air atapproximately inlet pressure to the chamber.

2, An air line lubricator comprising a body having an air conduit formedtherein including a zone or reduced crosssectional area, a bowl sealedt'o'the ltiwer surface of the body, a gauge glass sealedto the uppersurface or the body defining a chamber, said body having a firstp'al'ssagefo'r conveying air at inlet pressure into thebowl, a secondpassage for conveying oil from the bowl to the upper portion of thechamber, and a'third passage interconnecting the lower portion or thechamber with the zone of reduced cross se ti'onal area in the airconduit, a valve in said second passage, and conduit meansinterconnecting the said "chamber and air conduit for admitting alimited volume-of air at approximately inlet premure to'th'e chamber.

An air line lubricator comprising. a body having air conduitformedtherein including a zone or defining a chamber, said body having afirst pas sage for conveying air at inlet pressure into the a secondpassage for conveying oil irom the bowl to the up er portion of thechamber, and a third passage interconnecting the lower or the was :erwith the zone or reduced sectional a rcain the air conduit, a valve'insaid second passage, a conduit foradmitting'a limited volume air "atapproximately inlet pressure to the chamber, and 'a'bafiie in thechamber transverse to the conduit and spaced therefrom ior reducing airturbulence within the chamber.

4. An air line lubreator comprising a body having an air conduit formedtherein including a zone of reduced cross sectional area, a bowl sealedto the lower surface of the body, a gauge glass sealed to the uppersurface of the body defining a chamber, said body having a first passagefor conveying oil irom' the bowl to the upper portion of the chamber, asecond passage interconnecting the lower portion of the chamber with thezone of reduced'cross sectional area in theair conduit, and a thirdpassage for conveying air at approximately inlet pressure from the airbo'wl, a valve in said first passage, a conduit for adnrittingaii' theair inlet at approximately to the. chamber, the air delivery conduitbeing less than the air delivery capacity of said third passage, andbaiile means in the chamber near the discharge end of said conduit forreducing the turbulence 'of air in the -climber.

5. An air line lubricator comprising a body reduced cross sectionalarea, a bowl sealed to the lowersurface of-the body, a gauge glasssealed to -tlieiuppersurface of the body.

conduit to the sealed to the body, a hollow gauge glass sealed to thebody above the air conduit defining a chamber, first passage means inthe body for conveying air from said inlet portion to the bowl, secondpassage means in the body for carrying oil from the bowl to the upperportion of the chamber, third passage means in the body for carrying oiland air from the lower portion of the chamber to the center portion ofthe air conduit, a needle valve in the second passage for regulating theflow of oil therein, and a tube interconnecting the chamber with theinlet portion of the air conduit. said tube having an air deliverycapacity less than that of said third passage means.

6. An air line lubricator comprising a body having an air conduit formedtherein, including a center portion of reduced cross sectional area, aninlet portion and an outlet portion, a bowl sealed to the body, a hollowgauge glass sealed to the body above the air conduit defining a chamber,first passage means in the body for conveying air from said inletportion to the bowl, second passage means in the body for carrying oilfrom the bowl to the upper portion of the chamber, third passage meansin the body for carrying oil and air from the lower portion of thechamber to the center portion of the air conduit, a needle valve in thesecond passage for regulating the flow of oil therein, a tubeinterconnecting the chamber with the inlet portion of the air conduit,said tube having an air delivery capacity less than that of said thirdpassage means, and a bafiie over the discharge end of the tube in thechamber for deflecting air toward said third passage means.

CARL A. NORGREN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,782,741 Norgren Nov. 25, 19302,223,700 Norgren Dec. 3, 1940 2,442,777 Norgren June 8, 1948

